1. Field of the Invention
The present invention relates to a warning apparatus for an injection molding machine.
2. Description of the Related Art
Conventionally, an injection molding machine has an injection unit. The injection unit has a heating cylinder in which a screw is disposed rotatably and in an advancingly-retreatively movable manner. Drive means rotates and advances or retreats the screw. In a metering step, the screw is retreated while being rotated in a regular direction, so that resin is supplied from a hopper and heated in the heating cylinder, and molten resin is accumulated in a space located ahead of a screw head. In an injection step, the screw is advanced so as to inject the molten resin from an injection nozzle.
A mold unit is disposed in front of the injection unit. The mold unit includes a stationary platen, a movable platen, a stationary mold, a movable mold, and a mold clamping apparatus. The mold clamping apparatus advances and retracts the movable platen in order to bring the movable mold into contact with the stationary mold and separate the movable mold from the stationary mold, thereby performing mold closing operation, mold clamping operation, and mold opening operation.
During the period of injection molding, an operator must perform attachment and removal of the stationary and movable molds to and from the stationary and movable platens (hereinafter referred to as "mold exchange operation"), adjustment of the operation of the mold unit, adjustment of the temperature of the mold unit, heating of the heating cylinder, and charging of resin into the hopper.
Also, during the period of injection molding preparation, the operator must perform an operation for increasing the temperature of the mold unit, purging, exchange of resins, change of colors, removal of resin remaining within the heating cylinder, setting of molding conditions suitable for the molding unit, and starting up of molding.
However, since the operator performs various kinds of work or operation in the conventional injection molding machine, if the operator incorrectly operates the injection molding machine, the molding unit may be broken.